• Title/Summary/Keyword: Vietnam National University

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Assessment of Human Impact on Mekong River Flood by Using Satellite Nightlight Image

  • Try, Sophal;Lee, Giha;Lee, Daeeop;Thuy, HoangThu
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.187-187
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    • 2016
  • High intensity of population distribution in deltaic setting especially in Asia tends to have increased and causes coastal flood risk due to lower elevations and significant subsidence. Maximum or peak discharge of flood always causes numerous deaths and huge economic losses. New technology of spatial satellite image has been applied to analyze flood damage. In this research, the relationship of nightlight intensity associated with flood damages has been determined during 1992-2013 with spatial resolution of 30 arc sec ($0.0083^{\circ}$) which is nearly one kilometer at the equator in whole six countries along the Mekong River (i.e., China, Myanmar, Lao PDR, Thailand, Cambodia and Vietnam). ArcGIS Hydrological Flow Length Tool has been used to determine the distance of each pixel areas from the rivers and streams. Statistical analysis results highlight the significant correlation R = 0.47 between nightlight digital number and economic damages per unit area (US$/km2) and R = 0.62 for number of affected people for unit area ($people/km^2$). The areas near by the Mekong River and its tributaries correspond to high flood damage. This spatial analysis result is going to be prestigious key information to the regions and all related stakeholders for decisions and mitigation strategies.

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New Multiplier for a Double-Base Number System Linked to a Flash ADC

  • Nguyen, Minh-Son;Kim, In-Soo;Choi, Kyu-Sun;Lim, Jae-Hyun;Choi, Won-Ho;Kim, Jong-Soo
    • ETRI Journal
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    • v.34 no.2
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    • pp.256-259
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    • 2012
  • The double-base number system has been used in digital signal processing systems for over a decade because of its fast inner product operation and low hardware complexity. This letter proposes an innovative multiplier architecture using hybrid operands. The multiplier can easily be linked to flash analog-to-digital converters or digital systems through a double-base number encoder (DBNE) for realtime signal processing. The design of the DBNE and the multiplier enable faster digital signal processing and require less hardware resources compared to the binary processing method.

THE N-ORDER ITERATIVE SCHEME FOR A SYSTEM OF NONLINEAR WAVE EQUATIONS ASSOCIATED WITH THE HELICAL FLOWS OF MAXWELL FLUID

  • Ngoc, Le Thi Phuong;Dzung, Nguyen Vu;Long, Nguyen Thanh
    • Nonlinear Functional Analysis and Applications
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    • v.27 no.3
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    • pp.471-497
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    • 2022
  • In this paper, we study a system of nonlinear wave equations associated with the helical flows of Maxwell fluid. By constructing a N-order iterative scheme, we prove the local existence and uniqueness of a weak solution. Furthermore, we show that the sequence associated with N-order iterative scheme converges to the unique weak solution at a rate of N-order.

ASYMPTOTIC BEHAVIOR FOR STRONGLY DAMPED WAVE EQUATIONS ON ℝ3 WITH MEMORY

  • Xuan-Quang Bui;Duong Toan Nguyen;Trong Luong Vu
    • Journal of the Korean Mathematical Society
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    • v.61 no.4
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    • pp.797-836
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    • 2024
  • We consider the following strongly damped wave equation on ℝ3 with memory utt - αΔut - βΔu + λu - ∫0 κ'(s)∆u(t - s)ds + f(x, u) + g(x, ut) = h, where a quite general memory kernel and the nonlinearity f exhibit a critical growth. Existence, uniqueness and continuous dependence results are provided as well as the existence of regular global and exponential attractors of finite fractal dimension.

Partitioning of Recombinant Human Granulocyte-Macrophage Colony Stimulating Factor (hGM-CSF) from Plant Cell Suspension Culture in PEG/Sodium Phosphate Aqueous Two-phase Systems

  • Lee, Jae-Hwa;Loc, Nguyen-Hoang;Kwon, Tae-Ho;Yang, Moon-Sik
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.1
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    • pp.12-16
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    • 2004
  • Partitioning of human granulocyte-macrophage colony stimulating factor (hGM-CSF) was achieved in the aqueous two-phase systems (ATPSs) using a crude extract of transgenic tobacco cell suspension culture. This study examined the effects of polyethylene glycol (PEG) molecular weight and concentration and the effects of sodium phosphate concentration in different PEG/sodium phosphate systems on the partition coefficient, K. The best ATPS system was 5% PEG 8,000/1.6 M sodium phosphate after 2 h of incubation at room temperature. In this system, hGM-CSF was partitioned in the PEG-rich phase with a yield of 57.99% and K$\_$hGM-CSF/ of 8.12. In another system, 3% PEG 10,000/1.6 M sodium phosphate, hGM-CSF was also partitioned primarily in the top phase with a yield of 45.66% and K$\_$hGM-CSF/ of 7.64 after 2 h of incubation at room temperature.

Eudesmols Induce Apoptosis through Release of Cytochrome c in HL-60 Cells

  • Hoang, Duc Manh;Trung, Trinh Nam;He, Long;Ha, Do Thi;Lee, Myoung-Sook;Kim, Bo-Yeon;Luong, Hoang Van;Ahn, Jong-Seog;Bae, Ki-Hwan
    • Natural Product Sciences
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    • v.16 no.2
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    • pp.88-92
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    • 2010
  • We verified that the apoptosis activities were examined by DNA fragmentation, flow cytometric analysis with annexin V staining, activation of caspase-3, and cytochrome c release. In the result, $\alpha$- and $\beta$-eudesmol induced DNA fragmentation in HL-60 cells at a concentration of $80\;{\mu}M$, respectively. Additionally, pro-apoptotic cells sorted by flow cytometry analysis were detected in HL-60 cells to 31.77 and 29.67% with $\acute{a}$- and $\beta$-eudesmol of $80\;{\mu}M$. Thus, both $\alpha$- and $\beta$-eudesmol exerted caspase-3 activation and cytochrome c release at $80\;{\mu}M$ in HL-60 cells. These results are firstly reported that the sesquiterpenes, $\alpha$- and $\beta$-eudesmol are apoptosis inducers through mitochondria-dependent caspase cascade in HL-60 cells.

Molecular Characterization of a Korean Isolate of Human Norovirus, the Hu/NLV/Gunpo/2006/KO Strain (인체 노로바이러스의 한국분리주 Hu/NLV/Gunpo/2006/KO의 분자생물학적 특성)

  • Jeong, Ah-Yong;Yun, Sang-Im;Jee, Young-Mee;Kang, Yoon-Sung;Lee, Young-Min
    • Korean Journal of Microbiology
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    • v.45 no.2
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    • pp.105-111
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    • 2009
  • Norovirus (NV) with a variety of genotypes, a member of the family Caliciviridae, causes acute nonbacterial gastroenteritis in humans. We determined the nucleotide sequence of three open reading frames (ORFs) of a NV Korean strain and characterized the genetic relationship with others. The Korean strain designated Hu/NLV/Gunpo/2006/KO was isolated from the stool specimen of a 2-year-old female suffering from gastroenteritis. By performing reverse transcription and PCR amplification, three overlapping cDNAs were synthesized and used for direct sequencing. We found that like other NVs, this strain contains three ORFs: ORF1, 5,100 bp; ORF2, 1,647 bp; ORF3, 765 bp. Of 35 NVs, ORF1 had a level of genetic diversity lower than ORF2 and ORF3, of which the C-termini of the ORF2 and ORF3 showed a relatively high degree of genetic diversity. Phylogenetic analyses indicated that the Korean strain belonged to genogroup II, with Saitama U1, Gifu'96, Mc37, and Vietnam 026 being formed a single genetic cluster. The nucleotide sequence information of three ORFs of a NV Korean isolate will be useful not only for the development of a diagnostic tool and understanding of genetic relationship, but also provide important basic information for the functional analysis of their gene products.

The Effect of Post-Traumatic Stress on Depression of Korean and Vietnam War Veterans: Mediating Effect Analysis of Ego-Resilience (한국전, 베트남 참전 국가유공자들의 외상 후 스트레스가 우울에 미치는 영향에 대한 융복합적 연구 : 자아-적응유연성의 매개효과 분석)

  • Kim, Yunyoung;Hyun, Hye Sun;Choi, Nayoung;Kim, Tae Yeol
    • Journal of Digital Convergence
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    • v.17 no.11
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    • pp.547-556
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    • 2019
  • The purpose of this study was to investigate the relationship between post-traumatic stress and depression in veterans and to examine mediating effects of ego-resilience in relation. Data were collected from 383 subjects of National Merit of the Korean War or Vietnam War with the cooperation of the Daegu Veterinary Association from March to June 2018, and the collected data were analyzed using the SPSS 24.0 Statistics Program to analyze the mediating effects of ego-resilience in post-traumatic stress and depression with hierarchical multiple regression. Post-traumatic stress was found to be high in the case of long absence(F=7.97, p<.001), unemployment(t=2.09, p=.040), poor economic condition(F=64.49, p<.001), and ego-resilience as a parameter in the relationship between post-traumatic stress and depression. Based on the results of this study, it is required to develop various programs focusing on improving ego-resilience and systematic management at the national level in order to intervene in depression of veteran.

Rosa laevigata Michx. (Rosaceae): A Newly Alien Plant in Korea

  • Lee, Woong;Kim, Jung-Hyun;Kim, Jin-Seok
    • Korean Journal of Plant Resources
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    • v.34 no.3
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    • pp.197-202
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    • 2021
  • We found Rosa laevigata Michx., a newly alien plant in Songjinpo-ri, Jangmok-myeon, Geoje-si, Gyeongsang nam-do. Rosa laevigata is native to China, Taiwan, and Vietnam. It is reported as a naturalized species in Japan, South Africa, United States, and the Pacific Islands. Rosa laevigata is distinguished from R. multiflora by the large size of its flower. Its Korean name is 'Wang-jjil-re-na-mu' based on the large flower. Here, we provide precise description, taxonomic key to Korean Rosa species, illustrations and photographs of its habit.

Variation of American Exceptionalism: Saving Private Ryan and We Were Soldiers (미국 예외주의의 변주: 영화 <라이언 일병 구하기>와 <위 워 솔저스>)

  • Jin, Seonghan
    • American Studies
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    • v.44 no.1
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    • pp.155-182
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    • 2021
  • This study explores how American war films modify or reenact American exceptionalism depending on political and social situations in the United States. To this end, it analyzes the two war films, Saving Private Ryan and We Were Soldiers that were released before and after the 9/11 attacks as a critical juncture in the twenty first century, respectively. While the former conducts a partial modification on American exceptionalism in order to restore the national identity and moral authority of the United States lost ever since the Vietnam War, the latter demonstrates a complete reenactment of American exceptionalism in accordance with the foreign policy of the Bush administration and neoconservatism. It concludes with the illumination that the examination of American war films within the framework of American exceptionalism is efficacious in understanding from a broad perspective how American exceptionalism is utilized depending on political and social situations in the United States.